BTG’s revolutionary MEK-3000 TwinTorque™: introducing a new generation of easier, smaller, smarter, lighter instruments
Figure 1:
The new MEK-3000 TwinTorque
Accurate consistency measurement is the key to optimizing process and raw material usage, reducing additive and energy costs, and ensuring consistent quality. With a unique, patented design, BTG’s new consistency transmitter is the industry’s most advanced solution to today’s demanding production goals.
With over 80 years’ experience in consistency measurement, BTG can boast unrivalled expertise in this core facet of the papermaking process. In 1928, we launched the K3, the world’s first inline consistency transmitter, and in the early 1960s released the first transmitters to use our patented rotating shear force technology. With the launch of the MEK-3000 TwinTorque™, BTG has pioneered yet another breakthrough that’s setting new benchmarks for accuracy, reliability and ease-of-use.
As its name suggests, the TwinTorque’s twin motors – the centerpiece of BTG’s revolutionary patented design – deliver a host of advantages that are lifting papermaking performance to a whole new level.
Each motor is directly assigned its own separate axis, allowing for a very compact and lightweight design while at the same time improving accuracy and usability, and reducing maintenance overheads.
Rotating shear force is the leading consistency measuring principle when accuracy and instrument versatility really matter.
BTG’s unique TwinTorque technology delivers the precision of torque measurement for optimal accuracy. Improved accuracy in turn permits the use of fewer different types of sensing element – another advantage when it comes to maintenance and ease of handling. In addition, rotating consistency transmitters are virtually insensitive to variables like fiber composition and type, and, unlike microwave-based transmitters or nuclear-type density transmitters used for measuring pulp consistency, are unaffected by changing parameters like air content, pressure, dissolved material and conductivity.
Key benefits include:
Easier, smaller, smarter, lighter – the TwinTorque combines exceptional ease of use with small size, outstanding signal processing and lightweight design.
- Lowest possible installation costs through a single-phase power supply and simplified set-up
- Reduced need for a measuring vessel; a cheaper weld-in stud can be used for many applications
- Tightest possible process control through superior measurement precision, fastest response and shortest dead time
- Proven reliability of its measuring principle, making it ultra-versatile and universal
- Lightweight – at just 13kg, it can be easily lifted by one person
- Lowest maintenance: extremely robust construction based on proven solutions, with a minimum number of wearing parts
- Suitable as replacement system, since it adapts easily to existing MEK installations
- Comprehensive diagnostics for easy troubleshooting
Outstanding versatility makes the TwinTorque suitable for a huge range of applications, from the most routine to the most difficult. And since the standard version adapts itself to just about every challenge, there are fewer product iterations to deal with, simplifying operation and maintenance.
Setting the new standard for top-of-the-range performance
Consistency measurement is one of the most important control parameters in P&P. At Sweden’s Billerud Gruvön mill, around 90 consistency transmitters are currently installed – almost all of which have been supplied by BTG.
BTG’s TwinTorque can measure consistency over a range from 1-16%, delivering unrivalled accuracy and performance. Key applications include:
- Chemical pulping, where it controls consistency after a continuous digester, or after the blow tank
- Optimized bleach plant consistency control, where it serves as a reliable foundation for correct chemical dosing, minimizes chemical costs and improves pulp quality
- As a foundation for successful refiner control, optimizing paper machine runnability and profitability
- As a mechanism for safe, accurate and reliable paper machine control, including stock proportioning control, where accurate control of each fiber flow is essential for optimal product quality and minimized consumption of high-cost fiber
- As a way of improving basis weight stability through thick stock control
Maximum flexibility
The BTG MEK-3000 TwinTorque’s CPM is a new user-friendly interface that’s flexible and modular to meet all future communication demands. The CPM will serve as the platform for all future BTG sensors, and can be equipped with a range of modules supporting different communication protocols to match your needs. In addition to AMS maintenance tool and Emerson HART terminal support, the unit offers a range of advanced communication capabilities, such as Profibus PA, Fieldbus Foundation FF, and a new DTM capability.
Customer Case Studies
Metsä Tissue Katrinefors, Sweden
With a total production capacity of 75,000 tonnes/year, Metsä Tissue Katrinefors manufactures bathroom tissue, household towels, hand towels and industrial wipes. The mill has two tissue machines and several converting lines.
Metsä Tissue was BTG’s pioneer test site, with an MEK-3000 TwinTorque installed on PM36 after the mixing chest and before the machine chest. The pulp used is generally close to 100% recycled fibers of varying quality, with a small amount of bleached long fibers added to boost overall output quality. Production trials began in November 2007 and have continued without a break, with only some minor software glitches that were easily rectified by the BTG team.
Bengt Skalen from BTG shows Torbjörn Eriksson, Instrument Manager at Metsä Tissue, the serial design of the MEK-3000
Metsä Tissue team comments:
- Measuring values look good
- The transmitter’s small size and low weight make it easy to assemble and mount
- Motors integrated into the drive shaft mean no transmission breakdown
- Single-phase power supply makes installation much cheaper
- Low power consumption
Key data:
- Consistency: 2.5-4.5%
- Pressure: 3 bars
- Temperature: 35-45°C
- Flow: 0.7-1 m/s
- Pipe diameter: 300mm
Arctic Paper Munkedal, Sweden
Situated in Sweden’s south-west, Arctic Paper produces 170,000 tonnes/year of book paper, wood-free and wood-containing 4-color print quality paper, copying paper and OCR paper. The mill has two Fourdrinier machines with moduljet headbox and duo-former wire section (325/398cm).
Tests of the MEK-3000 TwinTorque began in December 2007, and have continued without a break. The transmitter is installed on PM8 between the mixing chest and machine chest, where different pulps are combined to obtain the required quality. Beginning of April 2008 the TwinTorque was taken into control.
Ake Olsson, Instrument Manager at Artic Paper Munkedal, looks at trends from the DCS
Arctic Paper team comments:
- Single phase power supply means no expensive connection to the switch room
- Low weight is good for the back!
- Motor drive looks interesting - no transmission to break down
- CPM junction box is handy and well-made – the drip protection is an innovative accessory
- Tests look promising – the MEK-3000 is now in control
Key data:
- Consistency: 1-4%
- Pressure: 0.3-0.5 bars
- Temperature: 40-50°C
- Flow: 2-3 m/s
- Pipe diameter: 200mm
Billerud Gruvön, Sweden
Billerud Gruvön is one of Sweden’s largest pulp and paper mills, with six paper machines and a production capacity of 685,000 tonnes/year, 250,000 tonnes of which is fluting. The mill also produces sulphate pulp, kraft paper, linerboard kraft, liquid packaging board, and bleached and unbleached sack paper.
Billerud Gruvön made for an ideal test site, not just because of its high production volumes and diverse product range, but because the mill is characterized by heavy vibrations which have caused the breakdown of previous equipment. Trials of the MEK-3000 TwinTorque began in March 2008, and to date no vibration damage has been detected.
Niclas Andersson from BTG inspects the prototype
Billerud Gruvön team comments:
- Single-phase power supply makes for considerable savings – a major advantage
- Size and weight make it easy to install and reinstall into the pipe
- Easier welding to main pipe – weld-in stud can be used down to 200mm pipe
- Fewer parts reduces maintenance overheads
- Design seems more resistant to vibration
Key data:
- Pulp: long-fiber screened unbleached
- Consistency: 2-5%
- Pressure: 3-4 bars
- Pulp temperature: 90-95°C
- Ambient temperature: 30-35°C
- Flow: 3-4 m/s
- Pipe diameter: 300mm
Equipment:
- Sulphate mill: 2 continuous digesters, bleach plants, flash dryer
- NSSC mill: 1 continuous digester
- Kraft paper mill: 3 multicylinder machines (430/520cm), 1 yankee machine (450cm),
- 1 combined machine (460cm). Off-machine coating
- Fluting mill: 1 multicylinder machine (670cm)
Holmen Paper Braviken, Sweden
Holmen Paper Braviken manufactures newsprint and colored newsprint on its three paper machines, with a total capacity of 760,000 tonnes/year. Pulp is mainly supplied by the company’s own TMP and DIP plants.
Trials at the mill began in January, 2008 with an MEK-3000 installed after reject refining and before the reject screen, and mounted via an adaptor ring in the same position as a previous MEK-2300 transmitter. Since this MEK-2300 had already been in control, the new MEK-3000 was put into control immediately on installation. Initial results have been very promising – so much so that Holmen Paper has taken an option to replace some of the eight MEK-2400 units currently on order for its new TMP plant with the newer MEK-3000 TwinTorque.
Holmen Paper team comments:
Bengt Skalen from BTG describes how to install the MEK-3000 to Anders Sundin, Group Manager Automation (left), and Rune Fredriksson, Preparation Engineer Automation.
- Looking great – the new design is a success
- No need for three-phase power supply – much cheaper installation
- Low weight means it can be mounted and removed by just one person with no need for lifting devices
- Seems to be a reduced maintenance overhead – no transmission
- Simpler installation for both pipe and electrical connections
Key data:
- TMP pulp after reject refining:
- Consistency: 3-6%
- Pressure: 2-3 bars
- Pulp temperature: 80°C
- Ambient temperature: 40°C
- Flow: 2 m/s
- Pipe diameter: 300mm